Question

How many moles of oxygen gas will be evolved
when 24.5 g of KCIO3, is heated for complete decomposition? (Molar mass of KCIO3= 122.5 g) ​

Answer 1

Answer:

0.3 moles

Explanation:

When potassium chlorate is heated potassium chloride and oxygen gas are formed .

To solve this question we first write a balanced chemical equation for the heating of potassium chlorate

2KClO3 → 2KCl + 3O2

We have the molar mass and the mass of potassium chlorate so it is easier for us to find the moles of potassium chlorate

Moles = mass/molar mass

24.5 ÷ 122.5 = 0.2 moles

Potassium chlorate and the oxygen gas formed react in the ratio 2 : 3

If 2 – 0.2 moles

3–?

You cross multiply to get

3 × 0.2 /2

0.6÷ 2 = 0.3 moles